Grading Your Diamond - The Four C's

Diamonds are extremely valuable, in fact are the most valuable gemstone today though there is very great variation in the prices which are commanded by different stones. In order to understand what determines the value of a diamond you must first learn how diamond quality is assessed and so equip yourself with the knowledge to know what makes a good buy and what you should be looking to avoid when you are buying a diamond ring or jewelry yourself.

The "Four C's" are the criteria by which a diamond is graded - they are:

· Cut

· Clarity

· Color

· Carat (or weight)

You should know that a diamond fresh from the mine looks like any pebble you may find on the beach; they are completely nondescript and look just like any other piece of rock except, once cut and polished the fire and brilliance within is brought forth.

The cut and polish process is the first stage of creating your diamond after it has been extracted (it takes about 250 tons of ore to produce one carat of diamond), the cut itself is performed so as much of the diamond is preserved as possible (i.e. keeps the weight as high as possible and minimizes any waste) but more importantly, how the cuts are made will determine how much light will enter and be internally reflected within the diamond itself. It is this ability to internally reflect light before it re-emerges from the stone which adds to the brilliance and fire of the diamond's appearance. The wrong cuts and the light will not reflect internally and so it will diminish in appearance; the right cuts and the fire and brilliance will be amplified. Cutting and polishing is understandably, a much sought after skill and requires a great deal of artistry and superb craftsmanship.

A carat is a measure of the weight of a diamond; one carat is equal to 0.2 grams but the term actually derives from the use of carob seeds to balance the scales when weighing a diamond; one carob seed was one carat. In practice, jewelers use carats and a point scale so 50 points is equal to half a carat. You must be aware that a carat is a measure of weight and not size - a diamond may appear larger due to how it is cut, but it may weigh less than another diamond which has a different cut. Keep this in mind; a carat is a measure of weight and not size or shape.

Diamonds are formed about 50 miles or more below the surface of the earth where the pressures are so intense that the carbon atoms which make up diamonds are compressed into a particular atomic formation. This is the structure which makes a diamond possess such qualities as very high strength and transparency. While the diamonds are forming in the earth, they may also include flaws created by bubbles of gas, inclusion of foreign matter, scratches and internal faults along the bonds between the lattice-work of carbon atoms. Sometimes these flaws are visible to the naked eye, sometimes not while a flaw may be located closer to the diamond's visible surface or buried deep within the body of the stone. The more visible flaws a diamond possesses the less valuable it is because of the less clarity it has.

Color is actually a misnomer - diamonds with no coloring at all are sought after as the absence of color increases the ability for a diamond to appear on fire; a diamond may have a yellow hue which dulls the brilliance of the stone. In this instance, the less color a diamond possess the more valuable it is though there are some pink and blue diamond stones which are highly prized because they are so very rare.

By Lawrence Reaves